Accurately determining and indicating the amount of fuel contained within a fuel tank can often be critical for a vehicle operator. The fuel amount may be used to determine when and where the vehicle should be refueled prior to the fuel tank being emptied.
A typical fuel tank utilizes a dedicated fuel level sensor, such as a floating sensor, to determine the amount of fuel remaining in the fuel tank. However, if the floating sensor becomes stuck, malfunctions, or becomes decoupled from the vehicle powertrain control module, the fuel level may become unknown. An in-dash fuel level indicator may provide an inaccurate or indeterminate fuel level to the vehicle operator. This may lead to the vehicle running out of fuel if the fuel level indicator suggests fuel is still remaining in the tank, or may lead to increased operator anxiety stemming from not knowing how much fuel is remaining in the tank.
The inventors herein have recognized the above problems, and have developed systems and methods to at least partially address them. In one example, a method, comprising: indicating a fuel level of a fuel tank based on a steady-state fuel tank pressure during a refueling event. In this way, a rate of fuel flow from a fuel dispenser into a fuel tank may be determined during the refueling event. The fuel flow rate may then be integrated over the duration of the refueling event to determine an amount of fuel added to the fuel tank.
In another example, a method for a fuel system, comprising: monitoring a fuel tank pressure during a refueling event; determining a fuel flow rate based on a steady-state portion of the monitored fuel tank pressure; and indicating an amount of fuel added to a fuel tank based on the fuel flow rate. In this way, a fuel tank fill level can be determined following a refueling event, even in a scenario where the fuel level indicator is stuck or malfunctioning.
In yet another example, a fuel system for a vehicle, comprising: a fuel tank configured to receive and store a liquid fuel; a fuel tank pressure sensor coupled to the fuel tank; and a controller configured with instructions stored in non-transitory memory, that when executed, cause the controller to: determine a fuel tank fill level prior to a refueling event; monitor a fuel tank pressure during a refueling event; determine a steady-state fuel tank pressure from the monitored fuel tank pressure; determine a duration of the refueling event; determine an amount of liquid fuel added based on the steady-state fuel tank pressure and further based on the duration of the refueling event; and indicating a fuel tank fill level following the refueling event based on a sum of the amount of fuel added and the fuel tank fill level prior to the refueling event. In this way, once a fuel tank fill level is established (for example, due to a full fuel tank indicated by an automatic shutoff event during refueling), the fuel tank fill level can be calculated in perpetuity despite the lack of a functioning fuel level indicator.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.